Heart disease is the number one cause of death in the world. Abnormal electric activity of the heart due to for example cardiac arrhythmia, including atrial fibrillation (AF) and ventricular tachycardia (VT) and congestive heart failure (CHF) are the fastest growing areas for both clinical and industrial development.
Electro-cardiographic mapping (ECM) is a non-invasive technique that provides detailed cardiac electrical activity information for the entire heart for each heartbeat by combining body surface electrical data acquired from a large number of surface electrodes with detailed three-dimensional anatomical data obtained from for example computer tomography (CT). It thus has the potential to deliver detailed electrophysiological information, which otherwise can only be measured with cardiac catheters in invasive electrophysiologic procedures. Additionally, ECM provides truly time-resolved transient electrophysiological data and multi-chamber information, while catheter data can only be acquired locally as a function of the cardiac cycle. Improved mapping and localization technologies as ECM will be critical to ongoing efforts to better diagnose and treat the above mentioned disease states.
FIG. 1 illustrates an image of a state of the art prototype ECM vest. The ECM vest is a multi-electrode vest (designated by reference numeral 50) with two multi-connector plugs for simple and fast connection of all individual electrodes 104. The individual electrodes 104 are connected to the multi-connector plugs via electric wires 102.
While FIG. 1a depicts a photographic image of the ECM vest, FIG. 1b depicts an X-ray image of the vest showing enlarged the arrangement of the electric wires 102 in more detail. As can be clearly seen, the close-up view in FIG. 1b shows that a multitude of electric wires are bundled in order to interconnect the electrodes 104 with the above mentioned multi-connector plug. Typically, each electrode is assigned a dedicated wire.
Multi-electrode vests for ECM like the one depicted in FIG. 1 will become important, both, as non-invasive diagnostic tools and during electrophysiological interventions where they can be used concurrently with catheters to obtain intracardiac signals. This avoids and shortens lengthy point-to-point mapping procedures or the necessity of large multi-electrode mapping devices.
Further, the U.S. Pat. No. 5,782,238 discloses an EKG devices comprising a pad with multiple electrodes. The electrodes are grouped into sets of electrodes, each correspond to a particular body size.
However, ECM requires the knowledge of the exact location of the surface electrodes in relation to the patient anatomy, including the cardiac anatomy. Herein, a ‘patient’ may be either a human being or an animal. For diagnostic use, the exact location of the electrodes in relation to the patient anatomy is currently obtained by computer tomography (CT).